1. Field of the Invention
The present invention relates to a capsule medical apparatus capable of moving in a stable posture in liquid introduced into a subject along a flow of the liquid, for example, and capable of performing an observation and medical practice such as obtaining an image inside the subject, for example.
2. Description of the Related Art
In recent years, in the field of endoscopes, there have been introduced capsule endoscopes provided with an imaging function and a wireless communication function. For the purpose of observation (examination), such a capsule endoscope is configured to sequentially image, using the imaging function, in an internal organ such as an esophagus, a stomach, or a small intestine (in a body cavity) along with peristalsis thereof, during an observation period after the capsule endoscope is taken into a patient being a subject (human body) from the mouth of the patient and until it is naturally eliminated from a living body of the patient.
It should be noted that, Patent Document 1 (International Publication WO 02/95351 Pamphlet (PCT National Publication No. 2004-529718)) discloses a technique suitable for an observation of a large intestine in which a capsule endoscope is taken with liquid to float in the liquid by setting the specific gravity of the capsule endoscope to be either the same as the liquid that surrounds the capsule endoscope, or one (1), which is the same as the specific gravity of water, thereby allowing the capsule endoscope to advance speedily in the body cavity to the large intestine. In addition, while only the proximity of the capsule endoscope can be observed when the capsule endoscope sticks to a wall surface of the body cavity, it is possible to ensure a field of view for observation and to observe everything according to Patent Document 1, because the capsule endoscope is made to float in the liquid for observation.
However, a problem has been noted that, when floating, the conventional capsule endoscope cannot move or stop along the flow of the liquid and a posture of the capsule endoscope becomes unstable, and therefore it is not possible to perform a desired observation or medical practice.